阳极和阴极溶解过程涉及不同的氧化物种
Timo Fuchs1, Valentín Briega-Martos2, Jakub Drnec3
1Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Olshausenstr. 40, 24098, Kiel, Germany.
Angewandte Chemie (International ed. in English)
|June 21, 2023
概括
燃料电池中的催化剂降解与表面氧化有关. 这项研究揭示了两种不同的氧化物阶段在氧化和还原周期中驱动溶解,影响催化剂稳定性.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
背景情况:
- (Pt) 基催化剂的降解是燃料电池性能和寿命的一个主要挑战.
- 电化学表面氧化和Pt的减少是促进催化剂降解的关键机制.
研究的目的:
- 研究电化学氧化-减氧循环期间Pt表面重组和溶解的原子尺度机制.
- 阐明不同氧化相在Pt溶解中的作用.
主要方法:
- 操作高能表面X射线衍射 (HSXRD) 用于原子级结构分析.
- 在线质谱 (MS) 检测溶解物种.
- 密度函数理论 (DFT) 计算以建模表面过程.
主要成果:
- 确定了两个不同的氧化物阶段,与不同的溶解机制相关.
- 阳极溶解与带状氧化物形成有关.
- 阴极溶解与第二个无形的Pt氧化物阶段 (类似PtO2) 相关,该阶段是在第一个氧化物和后形成的.
结论:
- 在电化学循环过程中的溶解是一个复杂的过程,由特定的氧化物相介导.
- 了解这些氧化物阶段及其形成对于设计燃料电池更稳定的Pt催化剂至关重要.
- 在最初的条纹状氧化物达到和覆盖范围后,表面重组变得独立于潜力.
相关概念视频
Electrodeposition
682
Electrodeposition is a technique used to separate an analyte from interferents by electrochemical processes. Here, the analyte is a metal ion that can be deposited on an electrode immersed in the sample solution. The electrochemical setup consists of an anode and a cathode. When an electric current is applied to the setup, oxidation occurs at the anode. At the cathode, which consists of a large metal surface, metal ions undergo reduction and deposit onto the surface.
Electrodeposition can...
Electrodeposition can...
682
Voltammetry: Stripping Methods
283
Anodic Stripping Voltammetry (ASV), Cathodic Stripping Voltammetry (CSV), and Adsorptive Stripping Voltammetry (AdSV) are electrochemical techniques used to determine trace amounts of analytes in solution. These methods involve applying a potential to an electrode and measuring the resulting current.
Anodic Stripping Voltammetry (ASV)
ASV is used to determine metals and metalloids at trace levels. It involves two steps: deposition and stripping. First, a negative potential is applied to the...
Anodic Stripping Voltammetry (ASV)
ASV is used to determine metals and metalloids at trace levels. It involves two steps: deposition and stripping. First, a negative potential is applied to the...
283
Controlled-Potential Coulometry: Electrolytic Methods
218
Controlled-potential coulometry, also known as potentiostatic coulometry, employs a three-electrode system in which the working electrode's potential is precisely regulated using a potentiostat. Platinum working electrodes are utilized for positive potentials, while mercury pool electrodes are favored for extremely negative potentials. The platinum counter electrode is separated from the analyte using a membrane or salt bridge to avoid interference in the analysis.
The chosen potential...
The chosen potential...
218
Electrogravimetric Analysis: Overview
280
Electrogravimetric analysis measures the weight of an analyte deposited electrolytically onto a suitable working electrode. This method involves applying a potential to a pre-weighed electrode submerged in a solution, which results in the desired substance being deposited through reduction at the cathode or oxidation at the anode. The electrode's weight is recorded after deposition, and the difference in weight gives the analyte's weight in the solution.
To test the completeness of the...
To test the completeness of the...
280
Properties of Transition Metals
26.4K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
26.4K
Electrolysis
26.8K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
26.8K


